1. Field of the Invention
The present invention relates to a slot machine capable of keeping a constant order or a constant tempo of stopping rotation reels.
2. Discussion of the Background
In a conventional slot machine as disclosed in U.S. Pat. No. 6,012,983 and U.S. Pat. No. 6,093,102, a symbol displayed on a rotation reel is scroll-displayed by rotation of the rotation reel installed on a front face of a casing, triggered by an insertion of a game medium, such as a coin and a bill, to a insertion slot of the slot machine and an input of a spin button by a player. Further, a to-be-stopped symbol is determined triggered by the input of the spin button. Then, after a predetermined time period has passed, the rotation reel is automatically stopped to stop-display the symbol.
Such a conventional slot machine is generally controlled such that a random number is generated by a random number generator triggered by the input of the spin button by the player and the symbol to be rearranged respectively to a plurality of rotation reels is determined according to the generated random number. For example, in a slot machine having a single line, the slot machine is controlled so that the symbol determined to be rearranged to each of the rotation reels is stopped on the single line. In that case, a position of the symbol on the rotation reel in rotation is detected by using an index detecting circuit, in which an index provided on the rotation reel is connected to a sensor or the like, and a number of pulses required for stopping the rotation reel at the symbol to be rearranged is inputted to a stepping motor which rotates the rotation reel, so that the symbol is stopped and rearranged to a predetermined position. Namely, in the conventional slot machine conducting such a stop control, the stop control for rearranging the predetermined symbol to the predetermined position is conducted in each of the plurality of rotation reels independently. Accordingly, as a result of the independent stop control in each of the plurality of rotation reels, there has occurred problems such as a generation of the case where an order of stopping the plurality of rotation reels is different in each game and the case where a tempo of stopping the plurality of rotation reels is not constant. More specifically, in the case that three rotation reels are provided, there may be a game in which a left reel stops first and a center reel stops next and a right reel stops last, and there may also be a game in which the center reel stops first and the right reel stops next and the left reel stops last. As thus described, there may be a case that an order of stopping three reels (left reel, center reel, right reel) is different in each game. Further, there may be a case that an interval time between stops of respective reels is not always constant.
In the conventional slot machine, the index of each reel is detected when a new game starts, in a state that a game result of a previous game is displayed to a display window of each reel. Then, the number of pulses required for stopping each reel at a to-be-rearranged symbol is calculated from sensing position of the index and the calculated number of pulses is inputted to the stepping motor of each reel. In this case, it is presumable that a difference in the number of pulses required for stopping at the to-be-stopped symbol among respective reels or a difference in the rotation angles up to the sensing position of the indexes of the respective reels may cause the above-described problems.
A present invention has been devised in view of the aforementioned circumstances and an object thereof is to provide a slot machine capable of keeping a constant order or a constant tempo of stopping rotation reels.
The contents of U.S. Pat. No. 6,012,983 and U.S. Pat. No. 6,093,102 are incorporated herein by reference in their entirety.